A. Field of the Invention
The present invention relates to a molded composite structure and a method of manufacturing a molded composite structure.
B. Background of the Invention
In general, most airplanes comprise a number of components such as a fuselage, an empennage, and wing structures. Wing structures are particularly important in the construction of airplanes because wing structures are the primary lift-producing structures and perform some of the key functions for these airplanes. For example, wing structures enable airplanes to take off and land, to change speed, and to change direction, as well as other functions. Furthermore, as one of the larger portions of the aircraft, the overall aerodynamic properties of the aircraft greatly depend on the wing structures. Finally, the cost of manufacturing the wing structures has a large impact on the overall manufacturing cost of these airplanes.
The ability of the wing structures to perform the functions discussed above directly depends on the design and construction of the wing structure. For example, the smoothness and weight of the wing structures directly impacts the wing structures ability to perform these functions.
In particular, the smoothness of the exterior of the wing structures affects the ability of the aircraft to take off and land, to change speed, and to change direction. If a wing structure has an uneven or non-smooth surface, this can create unnecessary drag, affecting the ability of the wing structures ability to perform many of the key functions. The aircraft will not be able to take off and land as easily, and it will be more difficult to alter the speed and direction of the plane during flight.
The weight of the wing structures also impacts the ability of the aircraft to take off and land, to change speed, and to change direction. The heavier the wing structures are, the more difficult it will be for the aircraft to take off and land. Further, heavier wing structures also make it more difficult to alter the speed and direction of the aircraft during flight.
The overall aerodynamic properties of an aircraft also depend on the design and construction of the wing structures. Ideally, airplanes are designed to create a smooth laminar flow of air over the aircraft. The smoother the laminar flow of air, the less energy is needed to fly the aircraft. This therefore reduces the fuel costs for the plane. If the wing structures are not designed to be aerodynamically sound, this smooth laminar flow will be disrupted. For example, if the wing structures do not have a smooth surface, added drag could result on portions of the wing structures. This will therefore increase the amount of fuel needed for flight.
The cost of manufacturing the wing structures also depends on the design and construction of the aircraft. The cost of the material used to manufacture the wing structures as well as the labor costs of manufacturing the wing structures greatly impacts the overall cost of the wing structures. Therefore, the design and construction of wing structures are particularly important in the manufacture of airplanes.
Currently, aircraft manufacturers use a number of different methods to manufacture wing structures. One such process uses a thin aluminum material to construct the structure. This process involves the manufacture of sheets of aluminum, which are machined and attached to one another to form the wing structures. Aluminum provides an inexpensive source of wing structure material. However, the manufacture of wing structures from aluminum is labor-intensive. A large amount of time is spent in manufacturing and assembling the aluminum sheets. In addition, while aluminum is a light-weight metal, it is heavier than other non-metal materials that could be used. Therefore, it causes the wing structure to be unduly heavy. Finally, the mechanical attachments associated with aluminum wing structures decrease the smoothness of the wing structure.
Another current process uses wet lay-up composites to manufacture wing structures. Composite materials are light and inexpensive, and unlike aluminum, can produce a smooth structure. However, like aluminum, constructing wing structures using wet lay-up composite materials is labor-intensive and expensive. The process of forming composite materials into the shape of a wing structure with this method requires complicated machining and tooling. Further, while composite materials are lighter than other materials, the wet lay-up process requires the use of a large amount of composite material. This increases the weight of the wing structures and thereby affects the performance of the wing structures.
Another current process to manufacture wing structures uses hand laid-out prepreg. Like composite materials, hand laid-out prepreg also results in a smooth structure. However, unlike aluminum and composite materials, the construction of wing structures from hand laid-out prepreg is not labor-intensive. However, prepreg is very expensive. Therefore, this method greatly increases the manufacturing costs.
Therefore, it is desirable to provide a molded composite structure that utilizes inexpensive material, is constructed using a nonlabor-intensive process, and provides a smooth laminar flow surface.
Methods and structures in accordance with the invention provide for a molded composite structure that is inexpensive, not labor intensive to produce, and has a smooth laminar flow surface.